| 摘要 |
A measuring device which has a tape connected at one end to one end of a shaft and the tape is scrolled around the shaft. The visible surface of the tape includes a scale having a set of marks which defines a system of measuring units. The tape is inserted into a tube and allowed to spring open against the inner wall of the tube. A measurement can then be obtained for the internal circumference of the tube or the internal diameter of the tube.
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